Carlos Celdran was demonstrating in support of new family planning laws during a mass at Manila’s cathedral in 2010. A court found Mr Celdran guilty of “offending religious beliefs” in a ruling made public on Monday. Human Rights Watch (HRW) called the verdict “a setback for free speech”.

“It was worth every moment,” Carlos Celdran, 40, told friends yesterday after Manila Judge Juan Bermejo Jr. sentenced him to over a year in jail for performing acts “notoriously offensive to the feelings of the faithful” in a place devoted to religious worship – a violation of Article 133 of the Revised Penal Code.

During the verdict, Celdran was dressed in the same 19th century garb of national hero Jose Rizal, which he wore when he burst into a ceremony at Manila Cathedral two years ago. He had held up a placard saying “Damaso” – the name of a predatory Spanish priest in one of Rizal’s anti-clerical satirical novels. Celdran had yelled out for the Catholic Church to stop meddling in politics by blocking passage of the Reproductive Health Law.

Among those present at the ceremony were several bishops and Manila Mayor Alfredo Lim, who had Celdran arrested. The lower court gave credence to the testimony of witnesses saying “the positive declaration of the witnesses for the prosecution and the circumstances surrounding the incident are sufficient to satisfy the quantum of evidence needed for a criminal conviction.”

The church which sued Celdran said it would issue a statement today. Convictions for the crime are rare and took place before the birth of the republic in 1946, according to Ibarra Gutierrez, professor of criminal law at the University of the Philippines.

He said a man was convicted before the second world war for holding a burial ceremony inside a Catholic cemetery for a non-Catholic. In a post-war case, which the top court reversed, a man was convicted of engaging a church minister in a debate during a religious ceremony.

“I find the whole idea of Article 133 archaic,” Gutierrez said. “More than a hundred years ago, we threw off the yoke of Spain, yet we are still dealing with this kind of law – a throwback to the Spanish era where the state and the church was one and the same.”

“Nobody should be jailed for voicing out an opinion or position, especially on a subject that concerns the lives of millions of Filipino women and mothers,” said HRW’s Asia researcher, Carlos Conde.

The sentencing comes fewer than two weeks after controversial new contraception laws came into effect in the Philippines. The legislation, which require health centers to hand out free condoms and birth-control pills, and introduces sex education in schools, was approved by parliament a month ago despite fierce opposition from the Catholic Church.

More than 80% of the population in the Philippines is Catholic, and the Church is closely associated with many politicians, media commentators and businessmen.

Mr Celdran said he planned to appeal and remains free on bail. “I am calm but I am going to fight this till the end,” he added.